This five year program of research will provide a controlled evaluation of the short and long-term effectiveness of self-help smoking cessation programs for women in a worksite setting. Two interrelated studies will be employed to determine the best format for administration (individual or group), and whether the unique resources available at the workside can be used to enhance treatment efficacy and influence smoking patterns among all smokers at the worksite, including the non-participants. Study 1 is a controlled, randomized trial that compares an individually-administered self-help protocol, a group-administered self-help protocol, and a minimal treatment control. The study will be conducted in three worksites to increase the sample size and generalizability (Total N=540). Multiple measures of outcome will be taken and subjects will be followed for 12 months. Smoking outcomes will include cessation and reduction rates and will be measured using self-report, saliva cotinine, and corroboration from a significant other. Mediating mechanisms will be examined including measures of social support. The results will provide a test of self-help smoking cessation programs at the worksite and which of the two self-help formats employed is the most effective. Study 2 will determine if the efficacy of the optimal self-help program, identified in Study 1, is significantly enchanced by the addition of an "organizational" component designed to maximized the unique resources available at the worksite. The organizational component includes media feedback, competition and other social influence procedures. This study will be conducted in four worksites; two will be randomly assigned to the self-help plus organizations component condition, and two to the self-help alone condition (N=300). Participants will be evaluated on similar measures and at the same times as outlined in Study 1. A combined cross-sectional and cohort telephone survey will also be employed in this study to evaluate the diffusion effects of the interventions on all smokers including non-participants. Results of both studies should yield sufficient information to identify an optimal worksite-based, self-help smoking cessation program that is replicable, relatively inexpensive, and fully utilizes the unique resources of worksite settings.